The present invention relates to a pneumatic tire, further in details, relates to a pneumatic tire capable of providing a unique outlook by changing reflection of light at a tire outer surface after exfoliating resin films by pasting two kinds or more of the resin films having different surface roughnesses to the tire outer surface.
Generally, it is important in view of promoting a commercial value of a pneumatic tire to promote an outlook of a pneumatic tire, particularly, an outlook of a side portion and various proposals have been made in background arts.
For example, JP-A-07-096719 (KOKAI) (reference 1) proposes a pneumatic tire providing a nylon film layer on an outer side of a side wall rubber layer in order to promote an outlook of the tire as well as a weather resistance thereof. Further, JP-A-03-292205 (KOKAI) (reference 2) proposes a pneumatic tire laminating a thin film comprising polyethylene of an ultra high molecular weight to a side wall surface in order to promote an outlook while providing an ozone crack resistance.
Further, JP-A-2000-142026 (KOKAI) (reference 3) discloses that in order to promote a glossiness of a surface of a molded tire and promote an outlook of the tire, a surface of a mold is formed by shooting beads having a predetermined particle size and a tire surface a surface roughness (Ra) of which falls in a range of 1.5 through 20 μm is formed by using the mold. Further, US 2003/0230370 A1 (reference 4) discloses that in order to provide a light reflecting face along an outer surface of a tire, by using a mold having an average surface roughness less than 0.381 μm, a side wall portion of the tire is molded.
Further, JP-A-06-106921 (KOKAI) (reference 5) discloses that in order to restrain a reduction in an outlook at a side wall portion by bringing about joint dent or the like, the side wall portion is partitioned into a plurality of fan-like regions in a peripheral direction, and a difference of surface roughnesses between the fan-like regions contiguous to each other is set to be equal to or larger than 50 μm.
According to technologies disclosed in the references 3 and 4 mentioned above, by rectifying the roughness of the mold surface, a glossiness of the tire side portion is promoted, however, at the time of vulcanizing and molding a tire the mold surface is adhered with a substance bloomed from inside of rubber constituting a tire main body and is stained thereby. Therefore, the stain is transcribed to the surface of the side portion to be colored in other than black color to pose a problem of deteriorating the outlook.
Further, according to the technology disclosed in the reference 5 mentioned above, a boundary between the regions is visualized by changing the surface roughnesses between the fan-like regions contiguous to each other, thereby, a recessed and projected mark of the joint dent or the like is camouflaged to restrain a reduction in an outlook. The difference in the surface roughnesses is constituted by changing the roughness of the mold surface as well as the references 3 and 4. Therefore, a problem similar to that of references 3 and 4 is posed.
On the other hand, according to technologies disclosed in references 1 and 2 mentioned above, the resin film is provided at the outer surface of the tire side portion. However, the film is to be completely adhered to the tire main body, and therefore, the film constitutes a portion of the tire outer surface in using the tire, thereby, a weather resistance or an ozone crack resistance is promoted. Therefore, in reference 1, in order to firmly adhere the nylon film layer to the side wall rubber layer, the nylon film is subjected to a pretreatment of adherence of RFL (resorcinol formaldehyde latex) treatment or the like. Therefore, the technologies do not intend to provide the resin film at the tire outer surface to be able to be exfoliated therefrom.
Meanwhile, generally, an outer surface of a side portion of a pneumatic tire is displayed with a mark constituted by character, numeral, sign indicating maker name, brand name, tire size or the like or a diagram of a tire rotating direction, a design pattern for dressing up the side portion. The mark generally projects from the outer surface of the side portion in background art, in this case, a mark is recessed at a surface of a mold for vulcanizing and molding a tire. However, although the method of forming the mark is suitable for mass production of a tire having a mark of the same design, the method is not suitable for producing tires having marks of various designs by small lots. Therefore, a promotion of an intention for a differentiation of a user in recent years cannot be met at low cost.